Molosser is a name for a group comprising several breeds of large, solidly-built dogs, probably all descended from the same root stock. The name derives from Molossia, a country once located in Western Greece.
Molossers are sometimes called "mastiffs." The proper noun "Mastiff," however, is used to refer to the English Mastiff, a breed that originated in England over two thousand years ago. Other terms include "MastÃn" (Spanish), "dogge" (Germanic) and "dogue" or "dogo" (romance languages).
Molossers typically have heavy bones, pendant ears, a relatively short and well-muscled neck, and a short muzzle. Although some Molossers are used for search and rescue.